It is widely known to provide various continuous and/or automatic feeding systems for copy sheets through copying or duplicating machines. Most such feed systems normally have been designed for relatively small copy sheets and often rely upon the inherent thickness of the sheets to facilitate the positioning, stacking and feeding function. For instance, the inherent thickness of relatively small copy sheets often is used to advantage in transporting the sheets and deflecting the sheets into various positions for copying.
Devices of the character described are not applicable for use with whiteprint, blueprint or similar copying machines which handle relatively large copy sheets. An example of such a copier is a machine which uses the diazo process where a translucent original is placed upon a relatively large sheet of sensitized diazo coated media and the two sheets are fed together through the machine. The sheets are carried around a transparent cylinder which contains an ultraviolet lamp. Wherever the light passes through the original to the copy, the sensitized coating on the copy is decomposed leaving the copy media white. Wherever the image on the original shields the copy media from the light, the sensitized coating will remain as a latent image. After being separated from the original, the exposed copy media passes into a developer station where a thin film of activator is applied. The activator combines with the coating in the latent image area and forms a visible image on the copy material. The copy then emerges from the machine as a flat, dry print ready for immediate use. This is but one type of copying machine to which the present invention is applicable, in that the size of the copy sheets may be as large as 24.times.36 inches or 36.times.48 inches. Other duplicating, printing or plotting machines have similar applicability.
Such copying machines as the diazo process machines exemplify a definite need for an improved feed system for large copy sheets through copying machines. As exemplified above, considerable time is expended by an operator in loading the machine with individual copy sheets. In the case of a diazo-type machine, the operator actually must feed both the original and the copy media, whereafter the sheets must be manually removed as they are running through and being discharged from the machine. It is readily apparent that manual handling of large copy sheets not only is a cumbersome process but also quite time consuming and labor intensive.
Another problem in handling large size copy sheets is in the area of storage. Conventionally, the copy sheets are stored in flat condition, sometimes in large drawer-like cabinets. Inventories of various sizes of large copy sheets present space problems.
Efforts to automate the feeding procedure of large copy sheets, for the most part, have centered around the use of a flat cassette-type storage unit and feed mechanism, similar to a standard office-type copier. However, such efforts do not solve the inventory/storage problems. In addition, loading and reloading such cassettes are extremely difficult, and the weight alone of such cassettes with large copy sheets limits their use to strong individuals. In addition, knives or shears to cut continuous wound roll media are sometimes used but add considerable manufactured cost and size to the machine as well as noise and service costs.
This invention is directed to solving the above problems and satisfying the need of a new feed system for large copy sheets. The invention has wide applications and is not limited to such machines as those using the diazo process since the concepts of the invention are equally applicable to any type of copying, duplicating, printing or plotting machine using large copy sheets.